1. Field of the Invention
The present invention relates to an endoscopic navigation method, and an endoscopic navigation system.
2. Description of the Related Art
More and more electronic video apparatuses are being applied in the field of colonoscopy, due to advanced development for image and electronic monitors. Specifically, electronic video devices, such as micro charge-coupled devices, are able to retrieve colored images from a colon. An electronic video endoscope is used to quantify and estimate of the health of a colon. Following image capturing by the electronic video endoscope, computer-aided diagnosis is performed to evaluate important features of the images. One significant feature of a colon sought by doctors is a lumen boundary, which is usually an abnormality in the colon. A doctor often determines the direction of a lumen according to a colon video, wherein expertise is used to manipulate an endoscope. Generally, various flecks appear on the dark area of an endoscopic video image and a lot of fold curves are scattered between the lumens and the intestinal walls. When the lumens are not in a homogenous region, there may be bright reflections from one of the intestinal walls, which make it difficult for the electronic video apparatuses to retrieve lumen border images.
There are several light sources at the tip of the endoscope used to illuminate the interior of a colon. Due to distance limitations, illumination of the surfaces of intestinal walls closer to the light sources is brighter than those further from the light sources. Consequently, the darker areas are usually in the direction or the region of the lumen. Meanwhile, the lumen region is not static. The lumen region changes according to size and shape of the lumen, background luminance and reflection characteristics etc., such that it is difficult for doctors to accurately judge the direction of the lumen. Furthermore, curves and bent portions of a colon adds to difficulty in identify the lumen by blurring images of the lumen. Note also, that if the insertion of an endoscope dose not follows the direction of the lumen, the tip of the endoscope may rub against the intestinal walls of a patient so that the patient feels uncomfortable.
Therefore, in order to solve the problems described above, the present invention provides an endoscopic navigation method and an endoscopic navigation system using a specific image process.